Tuning disorder in structurally colored bioinspired photonic glasses.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Colloidal crystals (e.g., opals) exhibit bright, iridescent colors but are angle-dependent.
• Colloidal glasses offer angle-independent structural color, tunable by particle size and arrangement, but typically lack vividness due to disorder.

Purpose of the Study:

• To develop an electrophoretic assembly platform for precisely controlling the level of disorder in colloidal particle systems.
• To tune the assembly kinetics and resulting photonic properties of colloidal films by manipulating the applied electric field.

Main Methods:

• Electrophoretic assembly platform to control particle disorder.
• Microscopy, X-ray scattering, and optical characterization to analyze assembled films.
• Systematic variation of electric field strength to tune assembly kinetics and order.

Main Results:

• Demonstrated tunable photonic properties of assembled films by altering the electric field.
• Identified an optimal range of order (approx. 3.2 particle diameters) for vivid, angle-independent structural color.
• Achieved optimal color brightness at a moderate electric field of ~15 V mm⁻¹.

Conclusions:

• Electrophoretic assembly provides a method to tune disorder and achieve desired structural color properties in colloidal systems.
• Angle-independent structural color with enhanced brightness is attainable in colloidal suspensions with controlled disorder.
• The findings offer a pathway for novel applications requiring tunable, vivid, angle-independent structural colors.